[skottie] Add missing SkUnicode include

Change-Id: I26223ee221fc703b8b00b0ba7173cce3011d3b45
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/762076
Commit-Queue: Jorge Betancourt <jmbetancourt@google.com>
Auto-Submit: Florin Malita <fmalita@chromium.org>
Reviewed-by: Jorge Betancourt <jmbetancourt@google.com>
1 file changed